People navigate the world best when they use shortcuts. Ticker symbols represent an asset in its short form for easier trading, such as Bitcoin - BTC or Tesla - TSLA.
With thousands of cryptocurrencies available, imagine how difficult it would be to have their full names always-on display. For example, Bitcoin Cash or Wrapped Bitcoin would be quite cumbersome to list on charts, exchanges, and your favorite crypto wallets and apps.
Instead, they are listed as BCH and WBTC. The sole purpose of a ticker symbol is to create a short and unique market identifier for every asset under the sun. It can be for commodities like Gold - XAU. It can be for stocks like GameStop - GME or it can be for cryptocurrency like Ethereum Classic - ETC.
No matter the category, each ticker symbol has to be unique, while its length can vary. For example, Polygon has a MATIC ticker symbol consisting of five letters. This is the maximum number of letters a symbol ticker can have if it were to be listed on Nasdaq, while on NYSE, the limit is four.
European exchanges are largely limited to three letters, while Asian exchanges tend to use numbers instead. For example, Tencent, the Chinese entertainment conglomerate, would have the TCEHY ticker symbol in the West. On Hong Kong's stock exchange, the same company would be listed under 0700.
Likewise, some exchanges add the country of origin to avoid confusion. Therefore, Apple (AAPL) would become Apple (AAPL.US) on FinTech platform AASTOCKS.com that covers both stocks and cryptocurrencies for the entire Asian market. Furthermore, companies can have different types of stocks. In that case, they would further differentiate, as is the case with Berkshire Hathaway - BRK.B and BRK.A - each denoting different voting rights.
In addition to making it easier to trade, ticker symbols prevent scams and accidents as well. You may have noticed that many tokens try to sound the same to take advantage of established brands. For instance, Polygon (MATIC) and Polymath (POLY) both sound similar, yet they have completely different ticker symbols.